import { Select } from 'antd';
import React, { Component } from 'react';

export default class Count extends Component {
    state = { count: 0 }

    // 加
    increment = () => {
        const { value } = this.selectNumber;
        const { count } = this.state
        this.setState({ count: count + value * 1 })
    }

    // 减
    discrement = () => {
        const { value } = this.selectNumber;
        const { count } = this.state
        this.setState({ count: count - value * 1 })

    }

    // 奇数再加
    incrementAdd = () => {
        const { value } = this.selectNumber;
        const { count } = this.state
        if (count % 2 !== 0) {
            this.setState({ count: count + value * 1 })
        }
    }

    // 异步加
    incrementAsync = () => {
        const { value } = this.selectNumber;
        const { count } = this.state
        setTimeout(() => {
            this.setState({ count: count + value * 1 })
        }, 500);
    }

    render() {
        return (
            <div>
                <h1>当前求和值:{this.state.count}</h1>&nbsp;
                <select ref={c => this.selectNumber = c}>
                    <option value="1">1</option>
                    <option value="2">2</option>
                    <option value="3">3</option>
                </select> &nbsp;
                <button onClick={this.increment}>+</button> &nbsp;
                <button onClick={this.discrement}>-</button> &nbsp;
                <button onClick={this.incrementAdd}>当前和为奇数再加</button> &nbsp;
                <button onClick={this.incrementAsync}>异步加</button> &nbsp;
            </div>
        );
    }
}